Field of the Invention
The present invention relates generally to cleaning devices and, more specifically, to cleaning device agitators having features for removing dirt and debris from the agitator.
Description of the Related Art
It is well known in the art of cleaning devices to use agitators to clean surfaces such as carpets, upholstery, and bare floors. These agitators can function in a variety of ways and appear in many forms. One typical embodiment of an agitator is a tube or shaft that rotates around its longitudinal axis and has one or more features that agitate the surface as it rotates. Such features typically include one or more bristle tufts, flexible flaps, bumps, and so on. These are commonly referred to as “brushrolls,” but other terms have been used to describe them. The agitator moves or dislodges dirt from the surface, making it easier to collect by the cleaning device. Agitators are useful in a variety of cleaning devices including vacuum cleaners, sweepers, wet extractors, and so on. In a sweeper, the agitator typically moves or throws the dirt directly into a receptacle. In a vacuum cleaner or similar device, the dirt may be entrained in an airflow generated by a vacuum within the cleaning device and thereby conveyed to a filter bag, cyclone separator or other kind of dirt collection device in the vacuum cleaner. U.S. Pat. No. 4,372,004, which reference is incorporated herein, provides an example of such an agitator.
It has been found that rotating agitators used in vacuum cleaners, floor sweepers, and the like, can collect a significant amount of various kinds of dirt and debris on the agitator itself. For example, the debris may include human and animal hairs, strings, threads, carpet fibers and other elongated fibers that wrap around or otherwise cling to the agitator. It has also been found that accumulated debris can reduce the performance of the agitator in a variety of ways. For example, debris may cover the agitation bristles and diminish the agitator's ability to agitate a surface. Further, debris on the agitator may impede the rotation of the agitator by wrapping around the axle or by creating additional friction with the cleaning head. If not removed, such debris can also accumulate on or migrate to the ends of the agitator and enter the bearing areas where it may cause binding, remove bearing lubrication, or otherwise generate high friction, excessive heat, or other undesirable conditions that can damage the bearings or mounting structure. In addition, debris collected on the agitator may create an imbalance in the agitator that may result in sound and/or vibrations when the agitator rotates.
Debris that has collected on an agitator is often difficult to remove because it has wrapped tightly around the agitator and intertwined with the bristles. Users of a cleaning device often must invert the device and remove the debris with manual tools such as knives, scissors or other implements. Manual removal can be unsanitary, time consuming and, if the user fails to follow instructions to deactivate the vacuum, may expose the user to contact with a moving agitator.
Some known devices use mechanisms and features to facilitate removing elongated fibers, such as string and hair, that may become wrapped around an agitator during use. For example, some agitators are provided with integral grooves that allow access by a pair of scissors or a knife blade to manually cut the fiber. Other cleaning devices use comb-like mechanisms to attempt to remove fibers. One example is shown in U.S. Pat. No. 2,960,714, which is incorporated herein by reference.
Still other devices, such as those shown in U.S. application Ser. No. 12/405,761, filed on Mar. 17, 2009 (Publication No. US 2009/0229075), which is incorporated herein by reference, use a movable blade to selectively press against the agitator to sever or abrade fibers. In the device in U.S. application Ser. No. 12/405,761, the agitator is provided with a raised support surface that provides a firm backing against which the blade presses to pinch and cut the fibers. Devices such as those in U.S. application Ser. No. 12/405,761 have been found to be effective for simple and durable user-friendly cleaning.
While various features of vacuum cleaner agitators and agitator cleaning devices are known, there still exists a need to provide alternatives, modifications, and improvements to such devices.